1. Field of Invention
The invention relates to a control technology for an internal combustion engine mounted in a vehicle.
2. Description of Related Art
An air fuel ratio control (fuel injection control) technology with higher accuracy becomes indispensable for coping with emission regulations that has been becoming increasingly severe year by year. In order to realize the air fuel ratio control with higher accuracy, the correction value for compensating the variation among internal combustion engines is calculated during operation of the internal combustion engine. Such calculation has been disclosed in Japanese Patent Application Laid-Open No. JP-A-2003-41976. The variation includes not only the one caused in the course of the production thereof but also the one caused by aging.
The calculation of the correction value during operation of the internal combustion engine for compensating the variation, however, may cause abrupt fluctuation in the torque, resulting in deteriorated drivability.